There will be speed counting tests, but a former counter said previous delays were due to poor management.

The 2010 general election was the first time votes were counted overnight in Northern Ireland.

Overnight counts did not take place for security reasons during the Troubles.

Slow vote

Northern Ireland's 2014 European election results required two days of counting.

This was attributed to the complexity of the single transferable vote system used in Northern Ireland.

The system is also used in the Republic of Ireland and Malta, who also declared their results after a similar period.

Following the 2014 elections the Electoral Commission, a watchdog that monitors elections in the UK, said: "There appeared to be a lack of overall management and oversight on the first day of the count resulting in some count staff not being used as effectively as they could have been."

Insider

A former vote counter spoke to the BBC on condition of anonymity, because of a confidentiality clause all counters have to sign.

The counter worked at Kings Hall, Belfast in the May 2014 election, and said "management was very disorganised. There were too many chiefs and not enough Indians".

The election worker said: "Communication with counters was very poor. Four hundred people were at a standstill for an hour and no information was given.

"Everyone stops when the calculations are being carried out. The calculations took a really long time."

The election worker also claimed:

Counters worked quickly, but were left idle for periods of time.

Staff were originally told the work would be over by around 19:00 GMT, but were asked to work until 01:00 GMT the next morning.

Counters were asked to bring in "nephews and nieces" to help with the count the following day.

Additional staff

Graham Shields, the chief electoral officer at Electoral Office for Northern Ireland (EONI) said the idea that the calculations done during a count could be hurried was "naive and simplistic".

He defended the level of management, describing supervisor training as "in-depth". He said it was carried out over a half-day or evening session, and that they used EONI's full-time staff and retirees that have performed the role previously.

He said that "some counters were good while others were poor", and a new recruitment test would allow them to "weed out those that are not up to standard".

The 2015 General Election is a first past the post ballot, which is easier to count than single transferable vote ballots. Mr Shields said the Northern Ireland results should be declared by the early hours of the morning after the ballot closes.

He also added that his teams had used a "contingency of additional staff", including council employees.

First past the post

The simplicity of first past the post ballots allow for counters to work through the night if needed. Single transferable vote ballots require counters to rest overnight.

Mr Shield noted that Scottish local elections, which also use the single transferable vote system, employ electronic ballots, and returned a result in just eight hours.